Countries, nationalities and languages 国家、国籍与语言

出国 (chūguó -- to go abroad) is a VERB (an action); 国外 (guówài -- abroad/overseas) is a PLACE noun, easily confused. Example: 我很想出国旅游，去国外看看不同的文化。(Wǒ hěn xiǎng chūguó lǚyóu, qù guówài kàn kan bùtóng de wénhuà.) -- I would love to go abroad to travel and see different cultures. Learn 出国 as the action and 国外 as the place you are in once abroad.

了 after the verb alone marks a completed action; a SECOND 了 at the end marks a state still true now. ✗ 我学了两年中文。(sounds finished) ✓ 我已经学了两年中文了，现在还在学。(Wǒ yǐjīng xuéle liǎng nián Zhōngwén le, xiànzài hái zài xué.) -- I have been learning Chinese for two years and am still learning. Add the sentence-final 了 (or 还在 + verb) when the learning is ongoing.

学 describes the ONGOING ACTION of studying, not the resulting ability; 会 (huì) states ability. ✗ 我学中文，所以我可以帮你翻译。✓ 我在学中文，可是我还不太会说。(Wǒ zài xué Zhōngwén, kěshì wǒ hái bú tài huì shuō.) -- I am learning Chinese, but I cannot really speak it well yet. ✓ 我学了三年中文了，现在会说一点儿了。(Wǒ xuéle sān nián Zhōngwén le, xiànzài huì shuō yìdiǎnr le.) 学 = the process; 会 = the resulting ability.

A language, like a course or subject, is an abstract skill-object counted with 门, not 个. ✗ 我在学一个新的外语。✓ 我在学一门新的外语。(Wǒ zài xué yì mén xīn de wàiyǔ.) -- I am learning a new foreign language. Learn the noun with its measure word as one chunk: 一门语言／一门外语／一门中文课 (a language / a foreign language / a Chinese course).

A 比-comparison never puts 很 (or 非常/太) before the adjective -- the comparison already carries the degree. ✗ 中文比法语很难。✓ 中文比法语难。(Zhōngwén bǐ Fǎyǔ nán.) -- Chinese is more difficult than French. To add degree, put 一点/得多 AFTER the adjective: 比法语难得多 (much harder).

得 marks a complement AFTER a verb; 地 marks a manner adverbial BEFORE a verb. Before a verb, use 地. ✗ 认真得练习 ✓ 认真地练习 (rènzhēn de liànxí) -- to practise conscientiously. The two are both pronounced de but do different jobs, so choosing by sound alone loses the mark.

是……人 states nationality; 住在…… states current residence -- they may be different facts and must not be merged. ✗ answering "你是哪国人？" with 我住在英国。✓ 我是德国人，可是我现在住在英国。(Wǒ shì Déguó rén, kěshì wǒ xiànzài zhù zài Yīngguó.) -- I am German, but I now live in the UK. Answer exactly the fact asked -- where FROM versus where NOW living are two different questions.